Quantitative liquid chromatographic-mass spectrometric analysis of amoxycillin in broiler edible tissues

A sensitive and specific method for the quantitative determination of amoxycillin (AMO) in broiler tissues (kidney, liver, muscle, fat and skin + fat) using liquid chromatography combined with positive electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) is presented. A liquid extraction using an aqueous 0.01 M potassium dihydrogen phosphate solution as the extraction solvent, was performed for a preliminary sample clean-up. After ultrafiltration, the extracts were further purified by solid-phase extraction using an octadecyl (C18) column. Ampicillin was used as the internal standard for AMO analysis. Chromatographic separation of the analytes of interest was achieved on a PLRP-S polymeric column (150 mm x 2.1 mm i.d., 100 Angstrom) using a mixture of 0.1 % of formic acid in water and acetonitrile as the mobile phase. Gradient elution was performed at a flow rate of 0.2 ml min(-1). The mass spectrometer was used in the MS/MS mode. The method was fully validated according to European Guidelines (linearity, precision, trueness, detection capability, decision limit, specificity and ruggedness) and the results fell within the ranges specified. Biological samples from broiler chickens that were treated orally with an amoxycillin formulation, were analyzed using the described method. Some results are presented. (C) 2004 Elsevier B.V. All rights reserved.